package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.Collections;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private SeckillVoucherServiceImpl seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
    private static final ExecutorService SECKILL_ORDER_EXELUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXELUTOR.submit(new VoucherOrderHandler());
    }
    private class VoucherOrderHandler implements Runnable{

        @Override
        public void run() {
            while (true){
                try {
                    //1. 获取队列订单信息
                    VoucherOrder voucherOrder = orderTasks.take();
                    //2. 创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                }
            }
        }

    }
    private  IVoucherOrderService proxy;
    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //1.获取用户
        Long userId = voucherOrder.getUserId();
        //2.创建锁对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //3.获取锁
        boolean isLock = lock.tryLock();
        //4.判断是否获取锁成功
        if (!isLock) {
            log.error("不允许重复下单");
            return;
        }
        try {
            //获取代理对象
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }

    /**
     * 下单秒杀
     * @param voucherId
     * @return
     */
    @Override
    public Result seckillVoucher(Long voucherId) {
        //0. 获取用户
        Long userId = UserHolder.getUser().getId();
        //1. 执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString()
        );
        //2. 判断是否为0
        int r = result.intValue();
        if (r != 0){
            //2.1 不为0-没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //2.2 为0-有购买资格，把下单信息保存到阻塞队列
        long orderId = redisIdWorker.nextId("order");
        //2.2 保存到阻塞队列
        VoucherOrder voucherOrder = new VoucherOrder();
        //2.3 订单id
        long orderid = redisIdWorker.nextId("order");
        voucherOrder.setId(orderid);
        //2.4 用户id
        voucherOrder.setUserId(userId);
        //2.5 代金券id
        voucherOrder.setVoucherId(voucherId);
        //2.6 放入阻塞队列
        orderTasks.add(voucherOrder);
        //3. 获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        //3. 返回订单id
        return Result.ok(orderid);

     }



    //    @Override
//    public Result seckillVoucher(Long voucherId) {
//
//        //1. 查询优惠卷
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //2. 判断秒杀是否开始
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            //未开始
//            return Result.fail("秒杀未开始");
//        }
//        //3. 判断秒杀是否结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            //已经结束
//            return Result.fail("秒杀已经结束！！！");
//        }
//        //4. 判断库存是否充足
//        if (voucher.getStock() < 1) {
//            return Result.fail("库存不足");
//        }
//        // 获取锁
//        Long userId = UserHolder.getUser().getId();
//        //创建锁对象
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        //获取锁
//        boolean isLock = lock.tryLock();
//        if (!isLock){
//            //获取锁失败,返回错误信息或重试
//            return Result.fail("不允许重复下单（islock）");
//        }
//        //获取代理对象
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        } finally {
//            //释放锁
//            lock.unlock();
//        }
//    }
    @Transactional
    public  Result createVoucherOrder(Long voucherId) {
        //5. 一人一单
        Long userId = UserHolder.getUser().getId();
        // 各个用户加不同的锁
            //5.1 查询订单
            int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            //5.2 判断是否存在
            if (count > 0){
                // 用户购买过，不允许再次下单
                return Result.fail("用户已经购买过一次");
            }
            //6. 扣减库存
            boolean success = seckillVoucherService.update()
                    .setSql("stock = stock - 1")
                    .eq("voucher_id", voucherId)
                    .gt("stock",0) //where id = ? and stock = ?
                    .update();
            if (!success){
                //扣减失败
                return Result.fail("库存不足");
            }
            //6. 创建订单
            VoucherOrder voucherOrder = new VoucherOrder();
            //6.1 订单id
            long orderid = redisIdWorker.nextId("order");
            voucherOrder.setId(orderid);
            //6.2 用户id
//        Long userId = UserHolder.getUser().getId();
            voucherOrder.setUserId(userId);
            //6.3 代金券id
            voucherOrder.setVoucherId(voucherId);
            save(voucherOrder);
            //7. 返回订单id
            return Result.ok(orderid);
    }

@Transactional
public void createVoucherOrder(VoucherOrder voucherOrder) {
    //6.一人一单
    Long userId = voucherOrder.getUserId();
    //6.1查询订单
    int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
    //6.2判断是否存在
    if(count>0){
        //用户已经购买过了
        log.error("用户已经购买过一次！");
        return;
    }
    //3.2库存充足扣减库存
    boolean success = seckillVoucherService.update()
            .setSql("stock = stock - 1") //相当于set条件 set stock = stock - 1
            .eq("voucher_id", voucherOrder.getVoucherId()) //相当于where条件 where id = ? and stock = ?
            .gt("stock",0).update();
    if(!success){
        log.error("库存不足!");
        return;
    }

    long orderId = redisIdWorker.nextId("order");//订单id
    voucherOrder.setId(orderId);
    voucherOrder.setUserId(userId);
    voucherOrder.setVoucherId(voucherOrder.getVoucherId());//代金券id
    save(voucherOrder);

}
}
